Motor driven fingernail filing devices can be useful for filing natural fingernails, but are especially advantageously employed for filing artificial fingernails to remove excess material from the artificial fingernails and to provide a smooth transition between the natural and artificial fingernail. Artificial fingernails can be applied by cementing a preformed plastic (e.g., acrylic) fingernail over a natural fingernail. An alternative method of applying artificial fingernails is to temporarily attach to the end of a finger an open mould which generally overlies the natural fingernail, apply a liquid thermosetting resin over the natural fingernail on to the open mould, and allow it to cure or harden into a solid. In either case, it is generally necessary to do a substantial amount of filing to conform the artificial fingernail to a desired shape and appearance, and to obtain smooth edges and smooth exposed surfaces. It is extremely fatiguing and time consuming to manually file artificial fingernails to the desired shape and smoothness, especially when this process is repeated a plurality of times. Accordingly, professional manicurists find it extremely beneficial to employ motor driven devices for filing and buffing fingernails in order to eliminate physical fatigue, save time, and reduce the risk of injury such as to the carpus of the manicurist on account of repeated manual filing.
Commercially available motor driven manicure devices have been generally limited to rigid wheels or burrs mounted on a rotatable shaft operatively coupled to the output shaft of a motor. These devices offer some time saving benefits and reduce physical fatigue for the user, but are generally poorly adapted for filing convex fingernail surfaces and edges, because they do not conform to the shape of the surface or edge to be filed. More specifically, while these conventional devices are very useful for filing the concave surfaces on the underside of a fingernail, the use of such devices for filing the top surface of a fingernail involves contacting a convex abrasive surface with a convex fingernail surface, which means that only a relatively narrow strip of the fingernail is being filed at any particular moment. Thus, great care in positioning, applying pressure, and repositioning these known devices must be exercised to smoothly file convex fingernail surfaces, and avoid filing grooves and other irregularities into the fingernail.
Another disadvantage with manicure devices having a rigid file element secured to a rotatable shaft is that the file element (wheel, burr, etc.) is not always easily replaceable, and the cost of the file element is not sufficiently low such that it could generally be regarded as a disposable part. The cost and difficulty associated with replacing the file element of these known manicure devices tends to discourage frequent replacement. Accordingly, such devices are not conducive to the promotion of good hygiene, because manicurists generally use the same file element on a plurality of different clients to avoid the time and expense associated with replacement of the file element.
Another disadvantage is that (wheel, burr, etc.) get dull causing excess heat build up. Because of the relative expense to replace a burr, the manicurists will tend not to change burrs as often as they should.
A still further disadvantage with manicure devices employing a rigid file element mounted on a rotatable shaft is that the file element is typically unshielded and filings, often in the form of minute particles, are thrown into the air where they can present a health risk if inhaled.
A manicure machine which employs a flexible, textured belt as a file element is shown and described by Watkins in U.S. Pat. No. 3,754,556. Watkins discloses that the machine includes flexible nail filing means which naturally yield to the arcuate shape of a fingernail impressed thereon. It is possible to press the edges of a fingernail through one of the narrow slots and against the textured belt causing it to yield and conform with the convex shape of the edge of the fingernail. However, because the textured belt is disposed beneath narrow slots in an upper housing wall or roof, it is impossible, or at least extremely difficult, to press the top of a fingernail against the textured belt to cause it to conform with the convex surface thereof.
The machine disclosed by Watkins also fails to overcome many of the remaining disadvantages inherent with conventional devices having rigid rotating file elements. In particular, replacement of the belt requires removing screws which secure the cover to the base, separating the cover from the base, removing one of the rollers from the associated support strut, replacing the belt, and reassembling the machine. Replacement of the belt in the device described by Watkins is even more difficult than replacing the wheels or burrs on most of the devices having rigid rotating file elements. Therefore, the machine disclosed by Watkins also fails to promote good hygiene, because most manicurists would tend to avoid the time and effort required to replace the belt for each new client.